PBX We are looking for VOIP, IP, GSM PBX with Capacity: Basic 4 CO lines, 16 extensions (416), expand to 424 and 832 Switch power Backup battery interface (optional) Billing software (optional) Transfer caller ID (optional) Intercom caller ID (optional) Auto-attendant (DISA:20s three paragraphs) Auto/Operator mode Automatic CO line detected External music input on holding Day/Night mode (optional) Real time clock (optional) Doorbell & door open function (optional) Alarmclock (optional) Private password CO line transfer to CO line External broadcasting interface (optional) Keyphone interface (optional) Intelligent Routing (LCR) (optional) Four exts.groups (optional) Call switch(call pick during conversation) (optional) Wireless Terminal Board(optional) Show More